There is a transfer system including a transfer apparatus that transfers a plate-shaped workpiece while holding it with a hand and a control device that controls the motions of the transfer apparatus. The transfer apparatus is provided with a plurality of motors that raise or lower a base and rotates the joint of an arm mechanism, drive sections, and various sensors. The transfer apparatus and the control device are connected by a number of electrical lines including main power supply lines for supplying electric power to the motors, communication lines for sending and receiving signals to control rotation of the respective motors, and signal lines for sending and receiving signals from the various sensors.
Japanese Patent Application Laid-Open No. 2011-259535 discloses a motor control system including a controller and a motor that are connected to a common DC power supply in which the controller controls the movement of the motor by power line communication.
Furthermore, Japanese Patent Application Laid-Open No. 2003-319693 discloses a motor control system in which current for driving a motor and a control signal are supplied through a common wiring system to thereby reduce the number of harnesses and connectors.